"future research work" is correct and usable in written English.
You can use it when discussing plans for future research. For example, "We plan to explore new methods in our future research work."
This constitutes our future research work.
This will be covered by future research work.
Directions for future research work in the field are included.
Finally, research gaps and scope of future research work are identified and discussed.
We have also highlighted important research issues in this field and identified future research work.
"Conclusion and discussion" section summarizes and discusses potential future research work.
Therefore, experimental results for comparison to theory are saved for future research work.
This our future research work should continue to be concerned about.
It is presently under study and the results will be presented in our future research work.
The paper concludes by providing the direction for the future research work in this domain.
In each section and in the end current challenges are discussed for future research work.
